Users of mobile devices often use the navigation capabilities of mobile devices for navigation purposes. This may include pedestrians who may need to be directed to an entrance of a building, or an operator of a vehicle who may need to be directed to an entrance to a structure such as a parking garage.
In mapping and navigation applications the locations and shapes of structures such as office buildings, amphitheaters, transit stations, parking garages and other facilities are often known, and matched to existing map data to display the structure along with other geographic features of a geographic area. Detailed features, however, are often not known for specific structures. For example, often the locations, sizes, and types of entrances and exits of structures cannot be determined from the basic cartographic data of a structure.
Traditional methods such as manually charting structure features can be very costly if applied on a large scale. For example, manually charting the features of the majority of the structures in a large city would require significant resources.